This invention relates to an image forming as a copying machine and more particularly to a device which forms an image by causing polarized light to be reflected by a document and exposing a photosensitive drum to this reflected light.
In a device for forming an image by causing light from a source to be reflected by a document and exposing a photosensitive drum to this reflected light it is customary to place the source of light under a transparent document table on which the document to be scanned is placed and either the document or the light source is moved with respect to the other such that the light from the source which scans the document is reflected by it and made incident onto the photosensitive drum. Such a document table is frequently provided with a cover which is openable and serves to keep the document pressed against the table surface. Such a cover is usually made of a non-transparent material so as to protect the user's eyes against the light from the source. Because of this non-transparency, however, the user is unable to ascertain if the document is correctly positioned on the table.